Did mine the same as ^^^^ when I was stock turbo on pcm controlled. Then, switching to e85 and mbc, let it hang and also being bigger turbo and running open turbo and 33-35psi, sensor being disconnected didn't hinder or rob any power.

The ambient air temp sensor is mostly used for emissions control calculations and in '05 cars it doubles as the battery temp sensor to, in part, control alternator output. If you datalog, you can use it to calculate intercooler temperature efficiency. Beyond that, like Tunerlover said, it's not as critical as the inlet temp sensor so hanging it in the fender won't hurt anything.